Play · gambling & expected value
Expected Value Machine
Updated 2026-07-31 · Sources: 1 · Concept: a small edge, repeated, is a certainty
Every commercial gambling product returns less than it takes; that is what makes it commercial. The share it keeps is small per bet and invisible on any single night, which is exactly why it works. This tool runs the arithmetic forward over a decade and sets it beside the same money invested instead. Nothing here depends on bad luck: the loss below is the average.
Predict first
$25 a bet, four bets a week, for ten years, on a standard sportsbook line. Losing nothing to luck, just the house margin, how much of it is gone?
Pick an estimate, or skip to your own numbers.
| Product | House edge | Expected loss |
|---|
About these percentages. The return-to-player figures behind this table are illustrative of each product type; they are not quotes for any operator, game, or jurisdiction. Real figures vary by game, state, and machine; lotteries publish theirs, most other operators do not. Do not cite these numbers as facts about a specific product. The argument does not rest on them: every commercial product returns less than it takes, and repetition turns any edge at all into a reliable outcome.
The invested counterfactual assumes the same annual outlay paid in monthly and earning 7%/yr, compounded monthly, modest against the long-run U.S. stock average (~10%/yr nominal, per investor.gov). Expected loss is total staked × house edge; it is an average over many repetitions, not a forecast of any one person's decade.
Wealth gotten by vanity shall be diminished: but he that gathereth by labour shall increase.Proverbs 13:11
KJV. The proverb contrasts wealth that arrives without work with wealth gathered a handful at a time, and it is a proverb, a statement of the ordinary way of things, not a promise that every windfall is cursed or every diligent worker gets rich. The table above is this verse with a spreadsheet attached.
If it has stopped being a choice. Compulsive gambling is not a budgeting problem and no calculator will fix it. Telling one person today (a spouse, a pastor, a doctor) is worth more than any number on this page, and confidential help lines exist in most countries. Related reading here: predatory products and how they find you and speculation versus investing.